I don't use them for cooking, but I do reuse them as pie weights -- they last for a long time this way. If you wanted to experiment with eating them post pie-weight, then I'd only do it with rice -- who knows, may taste toasted!

Thanks, hardlikearmour--you can probably tell this will be my first pie crust--I hadn't read the recipe closely yet and didn't realise the weights went on top of foil. But I still like the idea of shiny pennies as weights, so thanks for the tip!